This is Angel Wings, the OC (original character) pony — you’ve already seen mine — of young Alexis Heule:
You may also have noted that this same pony was a character in S06E24, “Top Bolt,” voiced by, yes, Alexis Heule. Sethisto explains:
When I first saw and heard Angel Wings in “Top Bolt”, I had the feeling that this was going to be the case. She is slightly different than your typical backgrounder, and fangirling over Dashie and Twilight is something a lot of us would probably want to do. Turns out there was a reason for it. A quick query over to Big Jim on Twitter revealed the real story… DHX has scooped up another kid from the Make-A-Wish foundation. Angel Wings was an actual little girl and fan of the show. And considering giant bows are the best thing ever, I can’t complain at all.
For “was,” read “is”: Angel Wings is still with us, for now.